Nothing like a little philanthropy to jog the memory.
A generous elderly man donated to seven poor youths a big chunk of his wealth, so they could get married. While attending the weddings, something caused the old man to remember his own wedding, as well as other lost memories--including all the people he had loaned money that never bothered to pay him back. The old man's debtors did not deny that they had "forgotten" to pay him back.
Now that his memory has been set right, it seems these borrowers will have to pay back what they probably had written off years ago as a freebie.
It pays to be generous at all times. As the saying goes, "your generosity will be returned countlessfold!"